An Empirical Research Report
Timothy J. Johnson
April 12th, 2007
ME595 – Manufacturing Tribology
Oakland University Introduction
Diamond is the hardest material known to man, in this day and age. Typically, diamonds have been known to demonstrate hardness values up to 12000 HV (Vickers Hardness) or approximately 100HRC. Diamond-coated Tungsten Carbide tools have demonstrated improved machining characteristics over coated tool steels commonly used today. With the increased use of composites, ceramics, and other ultra-hard / lightweight materials in numerous industries, diamond-coated machine tools are becoming more common since their performance improvements generally out weigh their increased cost.
This paper is an empirical summary of various research papers related to diamond coating processes of machine tools and their applicability to current and advanced machining processes. Topics to be discussed are: Diamond Coating Process Overview, Applications of Diamond Coated Tooling, Diamond Coated Tooling Machining Capabilities, and some conclusions on the topic. Though a few different tool coating processes are mentioned in this paper, the main focus is on CVD (Chemical Vapor Deposition) Diamond Tooling and its advances in the manufacturing industry.
Diamond Coating Process Overview
Since natural diamonds are very expensive, the machining industry has developed a multiple methods of creating man-made or synthetic diamond materials. These synthetic materials are then bonded to a substrate tool before they are suitable for machining. Discussed in this paper are threes different bonding techniques: Bonded Diamond Grit, PCD (Poly-crystalline Diamond) Diamond Tools, and CVD (Chemical Vapor Deposition) Diamond tools.
Bonded Diamond Grit Tools
Bonded diamond grit tools are the most common diamond-coated machine tools used in the industry. Their basic construction consists of crushed synthetic or natural
References: [1] – SAE Brazil Publication 982876 – Diamond Chemical Vapor Deposition on Cutting Tools – Barquete, Resende, Corat, Trava / Airoldi, Carlos De Moura Neto 1998 [2] – SAE International Publication 2006-01-3153 – CVD Diamond Coated Rotating Tools for Composite Machining – Engdahl 2006 [3] – SAE International Publication 2002-01-1526 – Edge Trimming of CFRP Composites with Diamond Coated Tools: Edge Wear and Surface Characteristics – Ahmad and Sridar 2002 [4] – Lubrication Engineering Publication Volume 40, 11, 681-685 – Reduction of Thermal Failure of Sintered Diamond Drill Elements – Bunting and Pope 1983 [5] – SAE International Publication 2003-01-0452 – The Surface Analysis of Powder Metallurgy (P/M) Components Machined by Diamond-like Carbon (DLC) Coting Cutting Tools – Chang, Smith, Littlefair, and Franks 2003